//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 3.0 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2004, The University of Texas at Austin
//  Dagoberto Salazar - gAGE ( http://www.gage.es ). 2008, 2011
//
//============================================================================

//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software.
//
//Pursuant to DoD Directive 523024
//
// DISTRIBUTION STATEMENT A: This software has been approved for public
//                           release, distribution is unlimited.
//
//=============================================================================

/**
 * @file ComputeDOP.hpp
 * This class computes the usual DOP values: GDOP, PDOP, TDOP, HDOP and VDOP.
 */

#ifndef GPSTK_COMPUTEDOP_HPP
#define GPSTK_COMPUTEDOP_HPP

#include "ProcessingClass.hpp"



namespace gpstk
{

/** @addtogroup DataStructures */
//@{


/** This class computes the usual DOP values: GDOP, PDOP, TDOP, HDOP
 *  and VDOP.
 *
 * This class is meant to be used with the GNSS data structures objects
 * found in "DataStructures" class.
 *
 * A typical way to use this class follows:
 *
 * @code
 *      // Create the input obs file stream
 *   RinexObsStream rin("ebre0300.02o");
 *
 *      // Loads precise ephemeris object with file data
 *   SP3EphemerisStore SP3EphList;
 *   SP3EphList.loadFile("igs11513.sp3");
 *
 *      // Sets nominal position of receiver
 *   Position nominalPos(4833520.3800, 41536.8300, 4147461.2800);
 *
 *      // Object to compute basic model data
 *   BasicModel basicM(nominalPos, SP3EphList);
 *
 *      // Declare a base-changing object: ECEF to North-East-Up (NEU)
 *   XYZ2NEU baseChange(nominalPos);
 *
 *      // Object to compute DOP
 *   ComputeDOP cDOP;
 *
 *   gnssRinex gRin;
 *   while(rin >> gRin)
 *   {
 *      gRin >> basicM >> baseChange >> cDOP;
 *   }
 * @endcode
 *
 * Please note that, in order to work appropriately, class ComputeDOP
 * needs that the GNSS Data Structure contains the values of the full
 * geometry matrix both for XYZ and ENU. This may be achieved if before
 * calling the ComputeDOP objects, we call objects from classes like
 * BasicModel and XYZ2NEU, among others.
 *
 * \warning If the GNSS Data Structure does not contain the necessary
 * geometric coefficients, ComputeDOP will return the corresponding
 * DOP values as -1.0.
 *
 * \sa BasicModel.hpp, ModelObsFixedStation.hpp, ModelObs.hpp,
 * ModeledReferencePR.hpp, ModeledPR.hpp, XYZ2NEU.hpp and XYZ2NED.hpp.
 *
 */
class ComputeDOP : public ProcessingClass
{
public:

    /// Default constructor
    ComputeDOP()
        : gdop(-1.0), pdop(-1.0), tdop(-1.0), hdop(-1.0), vdop(-1.0)
    { };


    /** Returns a satTypeValueMap object, adding the new data generated
     *  when calling this object.
     *
     * @param time      Epoch corresponding to the data.
     * @param gData     Data object holding the data.
     */
    virtual satTypeValueMap& Process( const CommonTime& time,
                                      satTypeValueMap& gData )
    throw(ProcessingException);


    /** Returns a gnnsSatTypeValue object, adding the new data
     *  generated when calling this object.
     *
     * @param gData    Data object holding the data.
     */
    virtual gnssSatTypeValue& Process(gnssSatTypeValue& gData)
    throw(ProcessingException)
    {
        Process(gData.header.epoch, gData.body);
        return gData;
    };


    /** Returns a gnnsRinex object, adding the new data generated
     *  when calling this object.
     *
     * @param gData    Data object holding the data.
     */
    virtual gnssRinex& Process(gnssRinex& gData)
    throw(ProcessingException)
    {
        Process(gData.header.epoch, gData.body);
        return gData;
    };


    /// Returns GDOP.
    virtual double getGDOP(void) const
    {
        return gdop;
    };


    /// Returns PDOP.
    virtual double getPDOP(void) const
    {
        return pdop;
    };


    /// Returns TDOP.
    virtual double getTDOP(void) const
    {
        return tdop;
    };


    /// Returns HDOP.
    virtual double getHDOP(void) const
    {
        return hdop;
    };


    /// Returns VDOP.
    virtual double getVDOP(void) const
    {
        return vdop;
    };


    /// Returns a string identifying this object.
    virtual std::string getClassName(void) const;


    /// Destructor
    virtual ~ComputeDOP() {};


private:


    /// Geometric Dilution of Precision
    double gdop;

    /// Position Dilution of Precision
    double pdop;

    /// Time Dilution of Precision
    double tdop;

    /// Horizontal Dilution of Precision
    double hdop;

    /// Vertical Dilution of Precision
    double vdop;

}; // End of class 'ComputeDOP'

//@}

}  // End of namespace gpstk

#endif   // GPSTK_COMPUTEDOP_HPP
